It is known to provide sports shoes or walking boots, and in particular soccer shoes, with studs in order to increase the grip of the shoe, in particular, on soft ground such as grass. The term “studs” is to be understood in the context of the present invention as meaning all possible elements which are arranged on outsoles of footwear in order to increase grip. The term “studs” is intended to include, for example, studs for soccer shoes, spikes for golf shoes, and studs for walking boots.
If the shoes are to be used on different ground conditions, it is advantageous if the studs are releasably attached to the sole to allow the shoes to be adapted to the different ground conditions. It has been known to attach studs to the soles of soccer shoes by means of threads. In addition to being able to adapt the shoe to a particular ground condition, worn studs can be replaced so that a new shoe is not necessary. If, however, during a soccer game (or a golf tournament) the studs must be replaced in a very short time due to changing weather conditions and/or changing ground conditions, screw studs anchored by screw threads or by additional pins or expanding elements, etc., are disadvantageous due to the time required to change the studs.
Other attachment systems exist where, for example, the stud can be “clipped” into a corresponding receptacle of the sole simply by inserting the stud without having to perform any additional assembly step. Such constructions are, for example, disclosed in U.S. Pat. No. 5,638,615 and U.S. Pat. No. 4,035,934, the disclosures of which are hereby incorporated herein by reference in their entireties.
U.S. Pat. No. 5,638,615 discloses a metal socket with a circular snap ring provided therein. The snap ring is made from flexible steel and, together with the socket, is embedded in a receptacle for the stud during the manufacture of the sole. When a base portion of the stud to be mounted is inserted, the snap ring is expanded before it snaps into an annular groove of the base portion and thereby fastens the stud. The rotationally symmetric form of the receptacle and the stud allows for rotation of the mounted stud in the receptacle.
Similarly, U.S. Pat. No. 4,035,934 discloses two metal spring pins arranged in a receptacle, which are deflected during insertion of a base member of the stud and engage a corresponding groove of the base member when the base member is completely inserted. The complete receptacle with the spring pin and other components is preassembled on a plate during the manufacture of the sole and is subsequently attached in a corresponding bore of the sole.
Disadvantages of the studs of U.S. Pat. Nos. 5,638,615 and 4,035,934 include the manufacturing complexity and the resulting costs. As previously mentioned, an initial preassembly of the receptacle assembly is required and the receptacle assembly is subsequently connected to the sole in a further manufacturing step. Also, the large number of small parts used renders automation difficult, such that a substantial amount of manual work is required. Further, there are metal parts used in the receptacle assembly that are susceptible to rust, and there is always the danger of losing a spring or a snap ring when the studs are replaced.
U.S. Pat. No. 5,848,482, the disclosure of which is hereby incorporated herein by reference in its entirety, discloses a stud, where the receiving unit and/or the mounting pin of the stud are made from a deformable elastomeric material. During insertion of the receiving unit and/or the mounting pin, the material is compressed and expands only in the mounting position of the stud, which is thereby fastened to the sole. This assembly allows for the stud to be detached from the sole. However, the force required to mount and release the stud is considerable due to the necessary compression of the material of the stud and/or receiving unit. Consequently, it is difficult to replace multiple studs on a shoe in a short duration of time.
It is, therefore, an object of the invention to provide a sole for the releasable attachment of at least one stud, which combines the advantages of an easy mounting of the stud with a simple and cost efficient manufacture of the sole and which does not require the use of a large number of small parts.